neat, never saw one before, just did some quick googling and found this, though its only what I've just found, and I'm not familiar with the noseband so I'm not supporting or condemning the below.... btw, how about a kineton instead? though perhaps a kinelton has the same possible drawback as below?

I would be really interested in your experience DOD, I have never seen one in action and can only make assumtions on the way it is constructed. My only concern is using it with a jointed mouthpiece.

The single-jointed mouthpiece applies pressure to the tongue, lips, and bars. Due to the V-shape of the bit when the mouthpiece is contracted, it causes a "nutcracker" action, which has a pinching effect on the bars. It also causes the joint of the bit to project forward and push into the sensitive roof of the mouth, causing the horse to lift its head to get away from the pressure.

It seems to me if you lift the bit up in the mouth the pressure on the lips, tongue and bars would be less but the joint, being higher in the mouth, would still project forward and being closer to the roof of the mouth would hit with a smaller, less harsh pull on the reins so the rider would need a very much lighter touch on the reins. The horse will still try to lift its head to get away from the pressure on the roof of its mouth but you are adding pressure on its nose, because the bit is physically attached to the noseband, forcing the horse to drop its nose.

As I said before I think the Worcester noseband would be effective with a straight mouthpiece but would advise caution using it with a jointed mouthpiece. I appreciate you are talking about using it with a straight mouthpiece, I just wanted to make it clear to anyone considering using a jointed bit what the consequences might be.

I Just from reading/looking - would have to think that the effect of the W on a jointed bit would not be that bad. Working merely on the theory that because the noseband holds the bit - the rider can't gain the same amoutn of pull soley on the bit cause the join to rise because the nose band stops the bit being pulled that far back - am I making sense?
It can also see it being fine with a double jointed bit in that the effects of having the point (which is eliminated with the 2 joins) is none exsistant in it - therefore the worries listed above would be a moot point.

My BIGGEST concern when first using it - in whatever bit - is that the horse would need to be used to stopping from nose pressure, when you ask for the whoa with this nose band on - you will not get anywhere near the same amount of pressure on the bars as you would without it, alternatively it goes to the nose and hence the need to for the horse to understand the nose pressure as whoa - or you are aimlessly pulling the reins having little evffect on the bars... i think i'm talking in circles now lol

Similar in principal to the Kineton, as others have mentioned, but perhaps more subtle. Because the Kineton has the metal part, and affects directly on the mouthpiece, it would be more of an "absolute", whereas I can see the Worcester being more foregiving... or maybe that would just be less effective...

Like any piece of tack, how your horse reacts may be different than John's horse or Mary's horse, even with the same bit and the same rider. Sometimes you just gotta try to know.